Enhanced heat exchange structure adopting double-layer sleeve

Abstract

The invention relates to an enhanced heat exchange structure adopting a double-layer sleeve, the enhanced heat exchange structure is composed of unit type double-layer sleeves, each unit type double-layer sleeve comprises an outer pipe and an inner pipe, the outer pipe and the inner pipe have an overlapping section in the axial direction, the inner pipe in the overlapping section is provided with a radial hole, and fluid is injected to the wall surface of the outer pipe through the radial hole. Through the design of the unit type double-layer sleeve and the combination of the radial hole jet flow impact technology, the boundary layer of a traditional heat exchange tube is effectively damaged, and the heat exchange efficiency is remarkably improved. Although the flow resistance is increased, the heat exchanger has obvious advantages in scenes with high requirements on heat exchange efficiency. Due to the modular structure and the flexible parameter adjustment capability, the system can be suitable for industrial scenes of efficient heat exchange, and has high practical value and popularization prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of shell and tube heat exchangers, and specifically relates to an enhanced heat exchange structure using a double-layer casing, which is suitable for industrial scenarios requiring efficient heat exchange. Background Art

[0002] At present, the heat exchange tubes in shell and tube heat exchangers mostly adopt a single tube structure. The tube side is the cooling medium, which flows along the tube bundle, and the shell side is the cooled medium, which flows perpendicular to the tube bundle.

[0003] Traditional heat exchange tube structure, such as Figure 1 As shown, the flow structure inside the pipe is a typical constrained fluid operation. There is a boundary layer on the inside of the pipe wall. The fluid flow rate decreases as the distance from the fluid to the wall decreases, resulting in a small heat transfer coefficient on the inside of the pipe and limited overall heat transfer efficiency.

[0004] Although there are many double-layer casing structures in the prior art, there are still some shortcomings:

[0005] For example, the energy-saving bidirectional heat exchange sleeve disclosed in patent document (CN202382614U) achieves heat exchange only through heat transfer between the outer and inner tubes, without actively disrupting the boundary layer, resulting in limited improvement in heat exchange efficiency. For example, the buried water-cooling jacket disclosed in patent document (CN213455080U) relies on the circumferential distribution of cooling water pipes in the interlayer and inner tube protrusions to enhance heat exchange, but does not form active impingement flow, resulting in a weak disturbance effect on the boundary layer.

[0006] Therefore, there is a need for an enhanced heat exchange structure that can actively destroy the boundary layer and significantly improve the heat transfer coefficient. Summary of the Invention

[0007] The present invention aims to solve the problem of low heat exchange efficiency caused by the presence of boundary layer in traditional single-tube and existing double-layer shell and tube heat exchangers. It proposes an enhanced heat exchange structure using double-layer shell and tube. By designing a double-layer shell and tube with a jet structure, the fluid disturbance is enhanced and the heat transfer efficiency is improved.

[0008] To achieve the above-mentioned purpose, the technical solution of the present invention is: an enhanced heat exchange structure using a double-layer casing, which is composed of a unit double-layer casing, and a single unit double-layer casing includes an outer tube and an inner tube. The outer tube and the inner tube have an overlapping section in the axial direction, and radial holes are opened on the inner tube in the overlapping section, and the fluid is ejected toward the wall of the outer tube through the radial holes.

[0009] Furthermore, a plurality of unit-type double-layer casings are connected in series to form a single heat exchange tube.

[0010] Furthermore, a plurality of radial holes are opened on the inner tube of the overlapping section, and the plurality of radial holes are evenly distributed along the circumference and axial direction of the inner tube 2 .

[0011] Furthermore, the axis of the radial hole is perpendicular to the axis of the inner tube.

[0012] Furthermore, the length of the overlapping section is 1 / 3-1 / 2 of the length of the outer tube.

[0013] Furthermore, the outer tube and the inner tube of the adjacent unit-type double-layer casing are sealed by argon arc welding.

[0014] Furthermore, the outer tube and the inner tube are made of stainless steel, copper alloy or titanium alloy.

[0015] Furthermore, the number of the unit-type double-layer casings is 2-10, which is adjusted according to the heat exchange requirements.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] After entering the inner tube, the cooling water flows through the jet holes on the inner tube wall toward the inner wall of the outer tube, creating impingement heat exchange. During impingement heat exchange, the boundary layer inside the outer tube is destroyed, resulting in a heat transfer coefficient far greater than that of traditional heat exchange tubes. This increases the turbulent kinetic energy of the fluid within the tube, thinning the boundary layer thickness in the downstream tube bundle and increasing the heat transfer coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the traditional single-tube heat exchange structure;

[0019] Figure 2 This is a schematic diagram of the unit-type double-layer casing structure of the present invention;

[0020] Figure 3 Schematic diagram of fluid flow in the heat exchange tube of the present invention;

[0021] Reference numerals: 1 - outer tube; 2 - inner tube; 3 - radial holes; 4 - overlapping segments. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] like Figure 2 As shown, the enhanced heat exchange structure using double-layer casing of the present invention is composed of unit-type double-layer casings. A single heat exchange tube is formed by welding a plurality of unit-type double-layer casings in series.

[0024] The single unit double-layer casing comprises an outer tube 1 and an inner tube 2, which have an axial overlap section 4. The inner tube in the overlap section 4 has radial holes 3, through which the fluid can form a jet and rush toward the wall of the outer tube 1.

[0025] The length of the overlapping section 4 is 1 / 3-1 / 2 of the length of the outer tube. The radial holes 3 are evenly distributed along the circumference and axial direction of the inner tube 2. The axis of the radial holes 3 is perpendicular to the axis of the inner tube 2.

[0026] The outer tube 1 and the inner tube 2 are made of stainless steel, copper alloy or titanium alloy.

[0027] The outer tube 1 and the inner tube 2 of adjacent unit-type double-layer casings are sealed by argon arc welding.

[0028] The number of unit-type double-layer casings is 2-10, which is adjusted according to the heat exchange requirements.

[0029] This structure is an optimization of traditional cooling tubes. Traditional cooling tubes are single-tube structures, where the coolant flows parallel to the tube wall. The heat transfer coefficient on the inside of the tube is lower. With the double-layered tube, the coolant flows through the jet holes in the inner tube and impacts the inside of the outer tube, creating impingement heat transfer and improving heat transfer efficiency.

[0030] After using double-layer casing, the flow inside the heat exchange tube is as follows: Figure 3 After the coolant enters the inner tube, part of the fluid is ejected through radial holes onto the inner wall of the outer tube, creating impact heat exchange and destroying the boundary layer inside the outer tube. The remaining fluid continues to flow along the inner tube and interacts with the jet flow of the downstream unit to increase the turbulent kinetic energy inside the tube, thinning the boundary layer thickness of the downstream tube bundle and significantly improving the overall heat transfer coefficient.

[0031] However, this structure will also increase the flow resistance. This structure is suitable for situations where the flow resistance is large.

[0032] During production, several unit-type double-layer sleeve structures are first processed, multiple sleeves are welded together in a specified order, and the entire cooling tube is expansion-welded to the tube plate to complete the installation.

[0033] This invention utilizes a unitized double-layer casing design, combined with radial hole jet impingement technology, to effectively destroy the boundary layer of traditional heat exchange tubes, significantly improving heat transfer efficiency. Although flow resistance increases, it offers significant advantages in applications requiring high heat transfer efficiency. Its modular structure and flexible parameter adjustment capabilities make it suitable for industrial applications requiring efficient heat exchange, demonstrating its high practical value and potential for widespread adoption.

Claims

1. An enhanced heat exchange structure using a double-layer casing, characterized by: It is composed of a unit-type double-layer casing. A single unit-type double-layer casing includes an outer tube and an inner tube. There is an overlapping section between the outer tube and the inner tube in the axial direction. The inner tube in the overlapping section is provided with radial holes, and the fluid is ejected toward the wall of the outer tube through the radial holes.

2. The enhanced heat exchange structure using double-layer casing according to claim 1, characterized in that: Several unit-type double-layer casings are connected in series to form a single heat exchange tube.

3. The enhanced heat exchange structure using double-layer casing according to claim 1, characterized in that: The inner tube of the overlapping section is provided with a plurality of radial holes, and the plurality of radial holes are evenly distributed along the circumference and axial direction of the inner tube 2 .

4. The enhanced heat exchange structure using double-layer casing according to claim 3, characterized in that: The axis of the radial hole is perpendicular to the axis of the inner tube.

5. The enhanced heat exchange structure using double-layer casing according to claim 1, characterized in that: The length of the overlapping section is 1 / 3-1 / 2 of the length of the outer tube.

6. The enhanced heat exchange structure using double-layer casing according to claim 1, characterized in that: The outer tube and inner tube of adjacent unit-type double-layer casing are sealed by argon arc welding.

7. The enhanced heat exchange structure using double-layer casing according to claim 1, characterized in that: The outer tube and the inner tube are made of stainless steel, copper alloy or titanium alloy.

8. The enhanced heat exchange structure using double-layer casing according to claim 1, characterized in that: The number of the unit-type double-layer casings is 2-10, which is adjusted according to the heat exchange requirements.

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